Vane assembly with improved vane roots
A vane for a vane assembly of a gas turbine engine includes a vane root connected to the airfoil portion opposite a tip thereof. The vane root includes a platform and a button portion interconnecting the platform and the airfoil position. The button portion has relatively blunt leading and trailing ends which respectively protrude beyond leading and trailing edges of the airfoil portion.
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This is application is a continuation-in-part of U.S. patent application Ser. No. 11/223,129 filed Sep. 12, 2005 now U.S. Pat. No. 7,530,782, the specification of which is incorporated herein by reference.
TECHNICAL FIELDThe invention relates generally to gas turbine engines, and particularly to improved inlet guide vanes provided therein downstream of the engine fan or low pressure compressor.
BACKGROUND OF THE ARTGas turbine engine vane assemblies are usually provided downstream of the engine fan and/or of a low pressure compressor to reduce the swirl in the air flow entering the high speed compressor. Such guide vane assemblies must be resistant to foreign object damage while having a minimal weight.
It is known to provide an outer shroud contained in the engine casing and having slots defined therethrough receiving the vane root therein to retain the vanes in place therewithin. In such a configuration, a grommet is usually inserted in the slots such as to surround a vane airfoil portion adjacent the root thereby isolating the vane from the shroud. However, during a foreign object damage event, a vane which is hit will move rearward as a result of the impact and the vane edge, which tends to be sharp, can cause cutting of the grommet and damage to other surrounding components. An adhesive such as a potting compound is sometimes used either in conjunction with or in replacement of the grommet, but the use of such an adhesive generally complicates the installation and replacement of vanes. In addition, the outer shroud used to retain the vanes in place increases the overall weight of the engine, as do the necessary connecting members to retain the vanes to this shroud, thus negatively affecting the engine's performance.
Accordingly, there is a need to provide an improved vane assembly.
SUMMARY OF THE INVENTIONIt is therefore an object of this invention to provide an improved vane assembly.
In one aspect, the present invention provides, a vane for a vane assembly of a gas turbine engine, the vane comprising: a tip adapted to engage an inner shroud; an airfoil portion extending from the tip and defining elongated relatively sharp leading and trailing edges; and a vane root connected to the airfoil portion opposite the tip, the vane root including an outer platform and an inner button portion interconnecting the platform and the airfoil portion, the button portion having relatively blunt leading and trailing ends respectively protruding beyond the leading and trailing edges of the airfoil portion, the platform protruding from the button portion along at least a transverse direction thereof.
In another aspect, the present invention provides a vane assembly for a gas turbine engine having an outer casing surrounding rotating blades of a rotor, the assembly comprising: a tubular wall portion of the outer casing located downstream of the blades, the wall portion having a series of circumferentially and regularly spaced apart openings defined therethrough; an inner shroud located inwardly of and concentric with the wall portion, the inner shroud and wall portion defining a flow path therebetween; a grommet sealingly engaged in each one of the openings, the grommet having a slot defined therethrough; and a vane for each grommet and extending radially between the wall portion and the inner shroud, each said vane having an airfoil portion extending between a tip and a vane root, the tip being engaged to the inner shroud, and at least part of the vane root being sealingly received in the slot of the grommet.
In a further aspect, the present invention provides a rotor assembly for a gas turbine engine, the rotor assembly comprising: rotating blades; an outer casing surrounding the rotating blades, the outer casing having a series of circumferentially and regularly spaced apart openings defined therethrough downstream of the blades; an inner shroud located inwardly of and concentric with the outer casing downstream of the blades, the inner shroud and outer casing defining a flow path therebetween; a grommet sealingly engaged in each one of the openings, the grommet having a slot defined therethrough; and a vane for each grommet and extending radially between the outer casing and the inner shroud, each said vane having an airfoil portion extending between a tip and a vane root, the tip being engaged to the inner shroud, and at least part of the vane root being sealingly received in the slot of the grommet.
Further details of these and other aspects of the present invention will be apparent from the detailed description and figures included below.
Reference is now made to the accompanying figures depicting aspects of the present invention, in which:
Referring to
Throughout this description, the axial, radial and circumferential directions are defined respectively with respect to the central axis, radius and circumference of the engine 10.
Referring now to
Referring particularly to
Referring back to
The inner recessed portion 58 will generally be referred to herein as the button portion. The button portion 58 includes relatively blunt leading and trailing ends 62, 64, which respectively protrude from the leading and trailing edges 38, 40 of the airfoil portion 36. The button portion 58 has a profile free of sharp edges. In use, the button portion 58 is received within an outer grommet 66 (see
Referring to
Referring to
In use, each grommet 66 is thus stretched and installed around the button portion 58 of the corresponding vane 30, with the circumferential portion 76 resting against the inner pressure surface 48 of the platform 46, as shown in
The vanes 30 of the vane assembly 20 are thus attached directly to the casing 24 without the need of an additional outer shroud. As such, damaged vanes can be replaced without the need to disassemble the entire engine 10, by simply removing the strap 86, sliding the damaged vane out of the corresponding opening 74 in the casing wall 68, sliding a new vane in place through the opening 74, and replacing the strap 86. In prior art configurations in which an additional outer shroud is used, this is not easily possible.
The blunt button portion 58 minimizes the risks of damage to the grommet 66 by the vane 30 through elimination of sharp edges in contact with the grommet 66. The enlarged button portion 58 also provides for the corresponding opening 74 in the casing wall 68 to be substantially larger than the airfoil portion 36 and tip 34 of the vane 30, facilitating the installation of the vane 30 which is done radially through the opening 74.
The vane assembly 20 eliminates the need for adhesives or potting components to retain the vane roots 32, which reduces costs and simplifies production and maintenance operations.
The absence of an outer shroud also lowers the overall weight of the engine 10. In addition, the larger openings 74 defined in the casing wall 68 lower the weight of the casing 24. The weight of the casing 24 is additionally lowered since the thickness of the casing wall 68 can be reduced with respect to a casing of the prior art used in conjunction with an outer shroud, as any loads transferred between a containment zone of the engine 10 and engine mounts in the event of foreign object damage or a fan blade failure are attenuated. Having a lighter casing 24 reduces the overall weight of the engine 10, thus improving engine performances.
The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without department from the scope of the invention disclosed. For example, the invention can be applied to vane assemblies contained in the casing of rotor assemblies other than fans and low pressure compressors. Other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.
Claims
1. A vane for a vane assembly of a gas turbine engine, the vane comprising:
- a tip adapted to engage an inner shroud;
- an airfoil portion extending from the tip and defining elongated relatively sharp leading and trailing edges; and
- a vane root connected to the airfoil portion opposite the tip, the vane root including an outer platform and an inner button portion interconnecting the platform and the airfoil portion, the button portion having relatively blunt leading and trailing ends respectively protruding beyond the leading and trailing edges of the airfoil portion, the platform protruding from the button portion along at least a transverse direction thereof.
2. The vane as defined in claim 1, wherein the button portion has a profile corresponding to that of the airfoil portion.
3. The vane as defined in claim 1, wherein the button portion protrudes from the airfoil portion around an entire perimeter thereof.
4. The vane as defined in claim 3, wherein the outer platform protrudes outwardly from the button portion about an entire perimeter thereof.
5. The vane as defined in claim 1, wherein the platform has an outer surface defined opposite of the button portion, and the platform includes a strap holder defined therein for receiving a fastening strap.
6. A vane assembly for a gas turbine engine having an outer casing surrounding rotating blades of a rotor, the assembly comprising:
- a tubular wall portion of the outer casing located downstream of the blades the wall portion having a series of circumferentially and regularly spaced apart openings defined therethrough;
- an inner shroud located inwardly of and concentric with the wall portion, the inner shroud and wall portion defining a flow path therebetween;
- a grommet sealingly engaged in each one of the openings, the grommet having a slot defined therethrough; and
- a vane for each grommet and extending radially between the wall portion and the inner shroud, each said vane having an airfoil portion extending between a tip and a vane root, the tip being engaged to the inner shroud, and the vane root including a button portion being free of sharp edges and sealingly received in the slot of the grommet.
7. The vane assembly as defined in claim 6, wherein the vane root includes an outer platform and an inner button portion interconnecting the platform and the airfoil portion, the platform being located outside of the outer casing and having a configuration preventing the platform from passing through the corresponding opening, the airfoil portion having a configuration allowing the airfoil to pass through the slot of the grommet, and the button portion being sealingly received in the slot of the grommet.
8. The vane assembly as defined in claim 6, wherein a portion of the vane root is located outside of the casing and defines a strap holder therein, the vane assembly further comprising a fastening strap received in the strap holder of each said vane and tightly surrounding the outer casing, the strap producing an inwardly directed force on the portion of the vane root located outside of the outer casing.
9. The vane assembly as defined in claim 7, wherein the platform has a strap holder defined therein opposite of the button portion, and the vane assembly further comprises a fastening strap received in the strap holder of the platform of each said vane and surrounding the outer casing, the strap producing an inwardly directed force on the vane platform.
10. The vane assembly as defined in claim 9, wherein the grommet includes a portion extending around the opening and being compressed between the outer casing and the platform.
11. The vane assembly as defined in claim 6, wherein the button portion has a profile corresponding to that of the airfoil portion.
12. The vane assembly as defined in claim 7, wherein the button portion protrudes from the airfoil portion around an entire perimeter thereof.
13. The vane assembly as defined in claim 12, wherein the outer platform protrudes from the button portion around an entire perimeter thereof.
14. A rotor assembly for a gas turbine engine, the rotor assembly comprising:
- rotating blades;
- an outer casing surrounding the rotating blades, the outer casing having a series of circumferentially and regularly spaced apart openings defined therethrough downstream of the blades;
- an inner shroud located inwardly of and concentric with the outer casing downstream of the blades, the inner shroud and outer casing defining a flow path therebetween;
- a grommet sealingly engaged in each one of the openings, the grommet having a slot defined therethrough; and
- a vane for each grommet and extending radially between the outer casing and the inner shroud, each said vane having an airfoil portion extending between a tip and a vane root, the tip being engaged to the inner shroud, and the vane root including a button portion being free of sharp edges and sealingly received in the slot of the grommet.
15. The rotor assembly as defined in claim 14, wherein the at least part of the vane root is free of sharp edges.
16. The rotor assembly as defined in claim 14, wherein the vane root includes a platform and a button portion interconnecting the platform and the airfoil portion, the platform being located outside of the outer casing and having a configuration preventing the platform from passing through the corresponding opening, the airfoil portion having a configuration allowing the airfoil to pass through the slot of the grommet, and the button portion being sealingly received in the slot of the grommet.
17. The rotor assembly as defined in claim 14, wherein a portion of the vane root is located outside of the casing and defines a strap holder therein, the assembly further comprising a fastening strap received in the strap holder of each said vane and tightly surrounding the outer casing, the strap producing an inwardly directed force on the portion of the vane root located outside of the outer casing.
18. The rotor assembly as defined in claim 14, wherein the button portion has a profile corresponding to that of the airfoil portion.
19. The rotor assembly as defined in claim 18, wherein the button portion protrudes from the airfoil portion around an entire perimeter thereof.
2914300 | November 1959 | Sayre |
3501247 | March 1970 | Tournere |
3849023 | November 1974 | Klompas |
3985465 | October 12, 1976 | Sheldon et al. |
4180371 | December 25, 1979 | Ivanko |
4305696 | December 15, 1981 | Pask |
4728258 | March 1, 1988 | Blazek et al. |
4820120 | April 11, 1989 | Feuvrier et al. |
4820124 | April 11, 1989 | Fried |
4907944 | March 13, 1990 | Kroger et al. |
4940386 | July 10, 1990 | Feuvrier et al. |
5074752 | December 24, 1991 | Murphy et al. |
5269649 | December 14, 1993 | Kiefer et al. |
5494404 | February 27, 1996 | Furseth et al. |
5547342 | August 20, 1996 | Furseth et al. |
6409472 | June 25, 2002 | McMahon et al. |
6494677 | December 17, 2002 | Grady |
6543995 | April 8, 2003 | Honda et al. |
6854960 | February 15, 2005 | Van Dine et al. |
20050022501 | February 3, 2005 | Eleftheriou et al. |
20050109013 | May 26, 2005 | Eleftheriou et al. |
840224 | April 1970 | CA |
Type: Grant
Filed: Aug 25, 2006
Date of Patent: Dec 8, 2009
Patent Publication Number: 20070098548
Assignee: Pratt & Whitney Canada Corp. (Longueuil)
Inventors: Barry Barnett (Markham), David Denis (Burlington)
Primary Examiner: Igor Kershteyn
Attorney: Ogilvy Renault LLP
Application Number: 11/467,413
International Classification: F01D 5/10 (20060101);